Pipa NPM | npm.io

PIPA

PIPA is a router and middleware extensions for ExpressJS.

Why PIPA

The idea of PIPA is about how to create ExpressJS router in an easy-way, readable and the middleware to be re-usable.

Installation

$ npm install pipa

How-To

There are two ways in how to use PIPA, simple-mode and advance-mode.

How-To-Simple-Mode

1 - Create your Express app and add PIPA.

var express = require('express')
var app = express()
var Pipa = require('pipa');

// Pipa
// @param   object      Express app
// @param   string      Router folder
// @param   string      Middleware folder

var pipa = new Pipa(app, 'router', 'middleware');
pipa.open();

app.listen(3000);

2 - Create a middleware folder

$ mkdir middleware && cd middlware

3 - Create a middleware file: Index.js

$ vi Index.js

4 - Add a showIndex function to Index.js

module.exports = {
    showIndex: function (req, res, next) {
        res.json({ message: 'Hello world PIPA!' });
    }
};

5 - Create a router folder in your folder project

$ mkdir router && cd router

6 - Afterward, create a route file: index.json

$ vi Index.json

7 - Add a http method, url path and also the middleware name to handle the request

{
    "GET /": "Index.showIndex"
}

Explanation: GET / means app.get('/', ...);, you can also use POST, PUT and DELETE methods.
Explanation: The Index.showIndex means that it will execute showIndex function in Index.js file under the middleware folder that we have created previously.
Explanation: The Index.json will automatically translated into / (root url path). For example, if you want to create a /user url path, you only need to create a User.json route file. So all routes inside User.json file will be able to be accessed under the /user url path, e.g. GET /:id, you can access it by /user/:id

8 - Now run your application by executing node app.js and access http://localhost:8000/ in your favorite browser.

How-To-Advance-Mode

In advance-mode, we will try to separate base url path and api url path. The router folder will look like below.

router/
    |- api/
        |- v1
            |- User.json
            |- History.json
        |- v1.2
            |- User.json
    |- Index.json
    |- User.json

Explanation: According to folder structure above, PIPA will automatically generate several endpoints as below.

API

/api/v1/user
/api/v1/history
/api/v1.2/user

BASE

/
/user

You can also use multiple middleware. For example, you want to get current user profile and need to check whether the request is authorized. The req.pipa object will come to rescue :D

In /api/v1/User.json router file, please add :

{
    "GET /me": [
        "Auth.ensureAuth",
        "User.getProfile"
    ]
}

Create a new middleware file Auth.js

module.exports = {
    ensureAuth: function (req, res, next) {
        // Check whether there's an `access_token` in the request
        if (!req.query.access_token) 
            return res.status(401).json({ code: 401, status: 'error', message: 'You are not authorized' });
        
        // Do some access token checking and pass it `req.pipa` to the next middleware
        req.pipa = { access_token: req.query.access_token, access_token_status: true };
        
        next();
    }
}

Afterward, in User.js middleware file, you can get the previous data by accessing the req.pipa object

module.exports = {
    getProfile: function (req, res, next) {
        if (!req.pipa.access_token_status)
            return res.status(500).json({ code: 500, status: 'error', message: 'access_token is not valid.' });
            
        // Get user profile based on `access_token` which you can get from `req.pipa.access_token`
        res.status(200).json({ code: 200, status: 'success', data: { user: { `user object` } });
    }
}